Thread replenishing mechanisms for sewing machines



THREAD REPLENISHING MECHANISMS FOR SEWING MACHINES Filed 1965 INVE OR-Michoel F. lvonko ZWA 7 ATTO EY United States Patent ABSTRACT OF THEDISCLUSURE A finger-like deflector for physically blocking the mouth ofa loop-seizing beak on a loop taker during the timewhen thread is woundon a bobbin in place in the loop taker to prevent the loop-seizing beakfrom seizing slack thread and attempting to pass it around the bobbinthereby breaking the thread.

This invention relates to thread replenishing .mechanisms for sewingmachines and more particularly to a loop deflector to prevent aloop-seizing beak from seizing loops of thread when thread is beingwound on a bobbin in place in a loop-taker.

While the present invention has utility in any bobbin threadreplenishing mechanism in which thread is wound on a bobbin while thebobbin is in place in a loop-taker, the accompanying drawing illustratesthe invention embodied in a loop-taker construction of thetype'disclosed in a United States patent of S. J. Ketterer et al., No.3,063,392, granted Nov. 13, 1962. In the United States Patent No.3,063,392, winding of replenishment thread on the bobbin is accomplishedby pressing a bobbin driver against the bobbin to rotate the bobbin anddeflect a first loop of thread seized from the needle by the loopseizingbeak onto the bobbin instead of allowing it to pass around the bobbin asin the formation of lockstitches. The bobbin driver has a clampingmember extending from its periphery to hold the thread against the backof the loop-seizing beak so that thread can be wound on the bobbin asthe bobbin is rotated by the bobbin driver. Unless a complicated needlereciprocation throwout mechanism is provided, during the time thatthread is being wound on the bobbin the needle will continue toreciprocate int-o the work-supporting bed. If the thread shouldaccidentally become slack in the vicinity of the loop-taker, theloop-seizing beak may seize the loop of slack thread and in attemptingto pass it around the bobbin would break the thread thus prematurelyending the bobbin thread replenishing operation.

It is, therefore, a primary object of this invention to provide a threadreplenishing mechanism with an automatic loop deflector for preventing aloop-seizing beak from interfering with a thread replenishing operationin a loop-taker.

The objects of the invention are accomplished by providing an automaticloop deflector having a finger-like member which physically blocks themouth of a loopseizing beak against seizure of loops of threadsubsequent to a first loop during a bobbin thread winding operation. Theloop deflector is L-shaped with one member fixed in a recess in the backsurface of a thread clamping member on the periphery of a bobbin driverand the other member adapted physically to block the mouth of theloop-seizing beak when the bobbin driver is pressed against a bobbinduring a bobbin thread winding operation.

Other objects and a fuller understanding of the invention may be had byreferring to the folowing description and claims, taken in conjunctionwith the accompanying drawing in which:

3,334,604 Patented Aug. 8, 1967 FIG. 1 is a top plan view of aloop-taker with a bobbin driver and a loop deflector in a retractedposition for sewing;

FIG. 2. is a top plan view of the loop-taker of FIG. 1 with the bobbindriver pressed against the bobbin for winding thread on the bobbin andthe loop deflector blocking the mouth of the loop-seizing beak;

FIG. 3 is a cross sectional view taken substantially along the line 3-3in FIG. 2; and

FIG. 4 is a perspective view of the bobbin driver and the loopdeflector.

With reference to the drawing, the invention is illustrated as embodiedin a sewing machine having a frame of which only a portion of awork-supporting bed 10 is shown. A needle 11 is mounted on the frame ina conventional manner for endwise reciprocation. The needle has an eye12 adapted to carry thread 13 from a source of thread supply (notshown).

Mounted in the bed to cooperate with the needle to form lockstitches isa loop-taker, indicated generally at 14, of the type disclosed in theaforementioned patent of Ketterer et al., No. 3,063,392. In general, thelooptaker includes a cup-shaped rotating member 15 carrying aloop-seizing beak 16 which rotates around a stationary bobbin case 17.The rotating member is secured to a bed shaft 18 by means of a setscrew19 screwed into a threaded bore 20 in a hub portion 21 of the rotatingmember.

The bobbin case 17 is held stationary by means of a lug 22 which ismounted on the frame and extends into a notch 23 in the bobbin case. Ahearing rib 24 on the bobbin case mates with a raceway 25 formed by anannular groove .26 in a flange portion 27 of the rotating member 15 anda gib 28 which is removably connected to the rotating member to closethe end of the raceway.

Journaled inside the bobbin case 17 on a screw 29 held in a threadedbore 30 in the bobbin case is a bobbin 31. The bobbin case also has aneedle aperture 32 and a thread tension spring 33. A thread cammingmember 34 connected to the rotating member 15 and having a cam ming edge35 cooperates with the thread tension spring and a stop member 36 on thethread tension spring at the beginning of each bobbin threadreplenishing operation in a manner presently to be described.

The bobbin thread replenishing mechanism includes a bobbin driver 37fixed on the end of a push rod 38 which is axially shiftable inside thehollow bed shaft 18 and mounted for rotation with the bed shaft. Thebobbin driver has a clamping member 39 on its periphery which slides ina gap 40 in the flange portion 27 of the rotating member 15. Theclamping member cooperates with a spring 41 which is mounted on therotating member to clamp thread seized by the loop-seizing beak 16against the back 42 of the beak during a bobbin thread replenishingoperation.

A recess 43 milled in the back surface of the clamping member 39accommodates an L-shaped finger or loop deflector 44 which has onemember 45 fixed in the recess by means of a screw 46 held in a threadedbore 47 in the clamping member. The other member 48 extends fingerliketoward the mouth of the loop-seizing beak 16. A curvilinear threadcamming surface 49 is formed on the leading edge of the finger-likemember.

In operation, during a sewing operation, the bobbin driver 37 remains inits retractedposition as shown in FIG. 1 so that the loop-seizing beak16 can seize loops of thread 13 from the needle 11 and pass them aroundthe bobbin 31 to form lockstitches. When it is desired to replenishthread on the bobbin, approximately degrees of rotation after theloop-seizing beak has seized a loop of thread from the needle the bobbindriver is pressed against the end of the bobbin to rotate the bobbin anddeflect the loop of thread onto the bobbin instead of allowing the loopto pass around the bobbin as in the formation of lockstitches.Simultaneously, the clamping member 39 on the bobbin driver presses thespring 41 against the thread to clamp the thread against the back 5 42of the loop-seizing beak so that subsequent rotation of the bobbin bythe bobbin driver will wind thread on the bobbin. The camming edge 35 ofthe thread camming member 34 in cooperation with pull exerted on thethread by the rotation of the bobbin deflects the thread into the threadtension spring 33 where it positions itself against the stop member 36.The loop deflector 44 blocks off the mouth of the loop-seizing beak 16so that the loop-seizing beak cannot seize any subsequent loop of threadfrom the needle until the bobbin driver 37 is retracted at the end ofthe bobbin thread replenishing operation. The curvilinear thread cammingsurface 49 assists in brushing away slack thread which might becomecaught on the loop deflector. Thus, a bobbin thread replenishingmechanism has been provided which is 20 capable of winding thread 13 ona bobbin 31 in place in a loop-taker 14 independently of needlereciprocation.

Although the invention has been described in its preferred form with acertain degree of particularity, it is understood that the presentdisclosure of the preferred form has been made by way of example andthat numerous changes in the details of construction and the combinationand arrangement of parts may be resorted to without departing from thespirit and the scope of the invention.

Having thus set forth the nature of the invention, what is claimedherein is:

1. A thread replenishing mechanism for a lockstitch sewing machinehaving a frame, thread supply means associated with the frame, a needlemounted in the frame for endwise reciprocation and having an eye tocarry thread, and a loop-taker mechanism mounted in the frame incooperative relation with the needle and having means for containingthread and a loop-seizing beak adapted to move in timed relation withthe needle to seize loops of thread from the needle to form lockstitchesby passing said loops around said means for containing thread, saidthread replenishing mechanism comprising means for selectivelyreplenishing thread from the thread supply into said means forcontaining thread while said means for containing thread is in place inthe loop-taker mechanism, and a finger-like deflector means forautomatically physically blocking the mouth of the loopseizing beakagainst seizure of loops of thread when thread is being replenished insaid means for containing thread.

2. A bobbin thread replenishing mechanism for a lockstitch sewingmachine having a frame, a thread supply associated with the frame, aneedle mounted in the frame for endwise reciprocation and having an eyeto carry thread from the thread supply, and a loop-taker mechanismmounted in the frame in cooperative relation with the needle and havinga bobbin mounted inside and a loop-seizing beak adapted to move in timedrelation with the needle to seize loops of thread from the needle toform lockstitches by passing said loops around said bobbin, said bobbinthread replenishing mechanism comprising means for selectively rotatingthe bobbin and deflecting a first loop of thread seized by theloop-seizing beak onto the bobbin instead of allowing the loop to passaround the bobbin, means rotating with the bobbin for holding anextremity of thread from the thread supply so that thread can be woundon the bobbin when the bobbin is rotated by said first means, and afinger-like deflector means for automatically physically blocking themouth of the loop-seizing beak against seizure of loops of threadsubsequent to said first loop when thread is being wound on the bobbin.

3. A bobbin thread replenishing mechanism for a lockstitch sewingmachine having a frame, a thread supply associated with the frame, aneedle mounted in the frame for endwise reciprocation and having an eyeto carry thread from the thread supply, and a loop-taker mechanismmounted in the frame in cooperative relation with the needle and havinga bobbin mounted inside and a loop-seizing beak adapted to move in timedrelation with the needle to seize loops of thread from the needle toform lockstitches by passing said loops around said bobbin, said bobbinthread replenishing mechanism comprising a bobbin driver selectivelyaxially shiftable against an end of the bobbin to rotate the bobbin anddeflect a first loop of thread seized by the loop-seizing beak onto thebobbin instead of allowing the loop to pass around the bobbin, meansrotating with the bobbin for holding an extremity of thread from thethread supply so that thread can be wound on the bobbin when the bobbinis rotated by the bobbin driver, and a loop deflector connected to thebobbin driver and shiftable with the bobbin driver physically to blockthe loop-seizing beak against seizure of loops of thread subsequently tosaid first loop when thread is being wound on the bobbin.

4. A bobbin thread replenishing mechanism for a lockstitch sewingmachine having a frame, a thread supply associated with the frame, aneedle mounted in the frame for endwise reciprocation and having an eyeto carry thread from the thread supply, and a loop-taker mechanismmounted in the frame in cooperative relation with the needle and havinga bobbin mounted inside and a loop-seizing beak adapted to move in timedrelation with the needle to seize loops of thread from the needle toform lockstitches by passing said loops around said bobbin, said bobbinthread replenishing mechanism comprising a bobbin driver selectivelyaxially shiftable against an end of the bobbin to rotate the bobbin anddeflect a first loop of thread seized by the loop-seizing beak onto thebobbin instead of allowing the loop to pass around the bobbin, aclamping member extending from the periphery of the bobbin driver forholding the thread against the back of the loop-seizing beak so thatthread can be wound on the bobbin when the bobbin is rotated by thebobbin driver, and a finger-like deflector member connected to saidclamping member and shiftable with the bobbin driver physically to blockthe mouth of the loop-seizing beak against seizure of loops of threadsubsequent to said first loop when thread is being wound on the bobbin.

5. A bobbin thread replenishing mechanism for a lockstitch sewingmachine having a frame, a thread supply associated with the frame, aneedle mounted in the frame for endwise reciprocation and having an eyeto carry thread from the thread supply, and a loop-taker mechanismmounted in the frame in cooperative relation with needle and having abobbin mounted inside and a loop-seizing beak adapted to move in timedrelation with the needle to seize loops of thread from the needle toform lockstitches by passing said loops around said bobbin, said bobbinthread replenishing mechanism comprising a bobbin driver selectivelyaxially shiftable against an end of the bobbin to rotate the bobbin anddeflect a first loop of thread seized by the loop-seizing beak onto thebobbin instead of allowing the loop to pass around the bobbin, aclamping member extending from the periphery of the bobbin driver forholding the thread against the back of the loop-seizing beak so thatthread can be wound on the bobbin when the bobbin is rotated by thebobbin driver and having a recess in the back surface, and an L-shapedloop deflector having one member fixed in the recess in the bobbindriver and the other member adapted physically to block the mouth of theloop-seizing beak against seizure of loops of thread subsequent to saidfirst loop when the bobbin driver is shifted to Wind thread on thebobbin.

(References on following page) 5 6 References Cited 3,038,429 6/ 1962Ketterer et a1 112-186 X UNITED STATES PATENTS 3,063,392 Ketterer944,740 12/1909 Madison 112181 JORDAN FRANKLIN, Primary Examiner.

1,794,255 2/1931 Stephenson 112-181 5 HERBERT R053 Examinen

1. A THREAD REPLENISHING MECHANISM FOR A LOCKSTITCH SEWING MACHINEHAVING A FRAME, THREAD SUPPLY MEANS ASSOCIATED WITH THE FRAME, A NEEDLEMOUNTED IN THE FRAME FOR ENDWISE RECIPROCATION AND HAVING AN EYE TOCARRY THREAD, AND A LOOP-TAKER MECHANISM MOUNTED IN THE FRAME INCOOPERATIVE RELATION WITH THE NEEDLE AND HAVING MEANS FOR CONTAININGTHREAD AND A LOOP-SEIZING BEAK ADAPTED TO MOVE IN TIMED RELATION WITHTHE NEEDLE TO SEIZE LOOPS OF THREAD FROM THE NEEDLE TO FORM LOCKSTITCHESBY PASSING SAID LOOPS AROUND SAID MEANS FOR CONTAINING THREAD, SAIDTHREAD REPLENISHING MECHANISM COMPRISING MEANS FOR SELECTIVELYREPLENISHING THREAD FROM THE THREAD SUPPLY INTO SAID MEANS FORCONTAINING THREAD WHILE SAID MEANS FOR CONTAINING THREAD IS IN PLACE INTHE LOOP-TAKER MECHANISM, AND A FINGER-LIKE DEFLECTOR MEANS FORAUTOMATICALLY PHYSICALLY BLOCKING THE MOUTH OF THE LOOPSEIZING BEAKAGAINST SEIZURE OF LOOPS OF THREAD WHEN THREAD IS BEING REPLENISHED INSAID MEANS FOR CONTAINING THREAD.